package com.dy.分类.链表.链表逆序1;


//206
/*
反转一个单链表。

示例:

输入: 1->2->3->4->5->NULL
输出: 5->4->3->2->1->NULL
 */
class ListNode {
    int val;
    ListNode next;
}

class Solution {
    public ListNode reverseList(ListNode head) {
        if(head==null){return null;}
        ListNode pre = null;
        ListNode current = head;
        while(current!=null){

            ListNode next = current.next;
            current.next = pre;
            pre = current;
            current = next;


        }
        return pre;
    }
}
